Safety-lock for elevator-doors.



w. E/DAY.

SAFETY LOCK FOR ELEVATOR DOORS. APPLICATION FILED JUNE 21. my

Patented Feb. 1919.

WALLACE E. DAY, or oAK AmJhoALIroRNIA, ASSIGNO To FRANK ivi. SPENCER,

DOING BUSINESS UNDER THE FRANCISCO, CALIFORNIA.

FIRM-NAME F SPEN 013m ELEVATOR C0,, OF SAN SAFETY-LOCK FORELEVATOR-DOORS.

Application filed June 27, 1917. Serial No. 177,283.

To all whom it may concern:

Be it known that I, \VALLAGE E. DAY, a citizen of the United States,residing at Oakland, in the county of Alameda and State of California,have invented new and useful Improvements in Safety-Locks forElevator-Doors, of which the following is a specification.

This invention relates to the type of safety lock for elevator doorswhich is held against releasement until the car comes to a full stopopposite the door. In most of the prior de vices this result is attainedby means of a guard released by means of a cam carried by the car, saidcam being normally retracted out of the path of the guard but by meansof complicated electrical mechanism projectable into the path of saidguard when the car stops opposite the door.

My object is to simplify and improve the construction and operation ofthe releasing mechanism for the guard. While I use a cam carried,preferably, on'the car and 00-. operating with guard-releasingmechanism,

it is not a receding cam but a simple fixed obstruction at all timesprojected into the ath of the releasing mechanism, and in order that,when the car is passing a door but not destined to stop opposite it, theguard 80 may not be released, I provide a simple electroma et to holdthe lock guard in place, notwitli standing the fact that the usualcamoperated releaslng means has been actuated. The electromagnet has itscircuit closed 85 through the main operating circuit for the elevator sothat only when the operating circuit is broken and the car is standingin position opposite the door, can the lock be operated.

40 One form which my invention may assume is exemplified in thefollowing description and illustrated in the accompanying drawings, inwhich Figure'l shows a side elevation of the lock casing, with the coverremoved.

Fig. 2 shows an end elevation of the same.

Fig. is a view indiagram, illustrating the wiring arrangement of theelevator controller and the manner in whlch the move-' ment of thecontroller lever establishes a circuit through the lock magnet.

Referring more in detail to the drawings,

I show a. casing 10 which is fitted in place on the door frame "and contains the entire Specification of Letters Patent.

- serves to retain the'paw patented net. as, 1919.

lock mechanism, which comprises a pivoted 65 dog 11 forming a guard fora latch 12, the latter carried by the door and having a hookshaped endto enter the casing. Said dog has a right-angular extension rigidlyformed thereon and carrying an armature 13 cooperating with anelectromagne-t l4. Pivoted coaxially with the pawl 11 is a rod 15 towhich is fixed at its inner end a crank arm 16 overlying the armatureand at its outer end, on the exterior .of the casing, a weighted arm 17,which is fitted at its end with aroller 18 to engage and cooperate withcam track 19 on the ear or cage of the elevator. The dog 11 and itsintegrally formed armature are loosely mounted upon the shaft 15 betweenbearing extensions of the crank arm 16. The magnet is connected inseries with the main operating circuit of the elevator preferablythrough the controller and direc tion switches not shown Normally thepawl is held in looking engagement with the latch by the action of aweighted arm. When the magnetis energized, the armature is-pulled downand the pawl held out to overlie the latch and retain the latter inlocked position. A spring 20 acts on the pawl to retract it and maintainit out of engagement with the latch when the weight of arm 17 isrelieved therefrom and the magnet 14 is deenergized. Normally, theweighted arm 17 causes the 5 crank arm 16 to press down on the armature13 and thereby retain the pawl 11 in position to act as a guardindependent of the action of the magnet.

In operation, when the car is near a door equipped with this lock, thecam 19 engages the roller 18 and moves the weighted arm to one side,thereby raising the crank arm 16 and taking the pressure off thearmature 13 and but for the magnet 14 the :pawl 11 might be moved awayfrom guard position under the influence of the spring 20. However,unless the car stops and the main oper ating circuit in which the magnet14 is included becomes broken, thus demagnetizing the magnet, this willnot /happen and the door cannot be unlatched. At other times when theoperating circuit is broken, as when the car is standing still at otherpoints than'the landings, then he weighted arm 1 5 in guard position.Unlatch'ng can be accomplished only when the car/is opp site the doorand standing still with the main operating circuit broken, at which timeboth the cam 19 and the deenergized magnet/'14 are in condition torelease the said pawl;

I also provide the usual. door switch so that when a door is open thecar cannot be operated. This may comprise spaced terminals 21 and 22with which a contact plate 23 cooperates to form an electricalconnection across, said plate being yieldingly mounted upon and movablewith a weighted lever Ql and held in contacting engagement with saidterminals by means of the latch hook 12. Vv'hen the latch hookis-released the weighted arm lifts the contact plate out of engagementwith the terminals and breaks the circuit. The terminals 21 and 22 ofall of the lock mechanisms are connected in serieswith an operating orcontrolling ariangement of the several parts herein shown and describedmay be employed without departing from the spirit of my invention asdisclosed in the appended claims.

7 It will be seen that before the car can be operated the door must beclosed and locked. This is so because the complete closing and latchingof the door is necessary to close the switch terminals 22-23, and thefirst effect of actuating the starting button of the controlling circuitis to energize the magnet 1d and thereby move the pawl 11 into placeabove the latch. Without the magnet 14 the door would remain unlockeduntil the roller g 18 had left the cam 19, which'ordinarily would notoccur until the car was a foot or I so above or below the landing.

Having thus described my invention, what I claim-and desire to secure byLetters Patent is 1.. A safety lock for elevator shaft .doors comprisinga lock case fixed to the-door .frames and having a bolt opening throughthe side wall thereof, a latch bolt carried by allowed to swing out ofengagement with the bolt, a main controller, an electric controllercircuit, an electromagnet within the case, an

electric circuit for said magnet adapted to be closed by movement of thecontroller arm, means actuated by the bolt upon its entrance to andengagement with the case to estabish said electric controller circuit,and separate means controlled by the magnet for above said bolt andpositioned within the I case, gravity means for normally holding thedetent in an obstructing position above the bolt, a spring men'iberopposing said 7 gravitv means-positive means carried by an elevator carto swing the gravity means from its holding position when the car is inregister with the doorway of the elevator shaft, and a separate memberadapted to be controlled by the electromagnet to swingthedetent into anobstructing relation to the bolt when the magnet circuit is closed.

3. An elevator lock comprising acase, a

said spring and normally holding the de-.

tent in an obstructing position above said latch bolt, positivelyoperated means carried by an elevator 'car whereby the weight upon thedetent may be relieved to allow it to swing from above the bolt, aswitch adapted to beclosed by the presence of the bolt within the case,a magnet disposed in relation to the detent to influence it whenenergized, and an electric circuit including said magnet and adapted tobe controlled by the movement of the main controller of the elevator,whereby the detent may be independently, operated to swing into alocking position.

l. A safety lockfor elevator shaft doors 'loclrbolt adapted to projectinto and encomprising a lock case having a bolt opening through the sidewall thereof, a latch bolt adapted tobe projected into said case and-topositively engage the wall thereof, a.

lever shaft disposed transversely of the case and above the bolt, abellcrank freely mounted upon said shaft and disposed with one of itsarms extending downwardly in an obstructing position above the lockbolt, a spring normally holding said arm out of engagement with the lockbolt, an electromagnet disposed in position to influence the oppositearm of the bell-crank to swing the first named arm into its obstructingposition above the bolt, gravity operated means fi-Xed to said shaft andadapted to normally hold the bell crank in'its obstructing position, aswitch closed bv the presence of the lock bolt within the case wherebythe circuit through ont oi an obstructing an elevator controller circuitmay be completed, and means carried by the elevator car to relieve thebellcraisk from the pressure of the gravity means ndependently of theaction of the electromagruet.

f. A lock for elevator doors comprising a case having an opening throughthe side wall thereof a latch bolt -t-arried by the door and adapted tobe projei led into and to positively engage the case. a detent withinthe case, a pivot shat't ev'z-nding transversely ot' the ease and suppoting the detent above the lock bolt and in a position to obstruct theremoval of said boll trom the case, a spring acting to normally h ldsaid detent: positioe. an armature formed integral with said o' tent andextending in a substantially horizontal plane. anelectromagnet disposedbeneath the armature to intiuence it in a downnard direction, a crankarm tixed to the pivotshat't independently ot' the detent and armature,a counterweight arm fixed to said shaft exteriorly of the case andadapted to exert a downward pressure upon. the arn'iature by the crankarm, a roller upon the end of said counterweight arm, a cam membercarried by the elevator 'ear and adapted to engage the roller to relievethe'weight of the counterweight from the top of the armature acontroller circuit switch adapted to be closed by the oresence of thelock bolt within the ease, and a separate electric circuit ineluding themagnet, whereby the movement of the controller of the c; r to close itscircuit will cause the detent to be swung out-- wartlly by the action ofthe magnet to prevent the removal of the bolt from the case irrespectiveof the action of the counter weight arm.

6. An elevator door lock comprising a lock case... an electric switchmember within said case, gravity means for normally holding said switchopem an electromagnet, an electric circuitaincluding the magnet, a latchbolt adapted tb be projected through an openingin the wall of the lockcase to engage the same and to close said switch, a pivoted detentdisposed above said bolt gravity means tor normally holding the detentin an obstructingposition above the bolt, a yieldable member opposingsaid gravity means,'-positive means carried by an elevator car to swingthe gravity means from its holding position when the car is in registerwith the doorway of an elevator shaft, and means adapted to becontrolled by the electro-inagnet to swing the detent into obstructingrelation to the bolt when the 1nagnet circuit is closed.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing; witnesses.

WALLACE .DAY. llitnesses:

W. \V. Her-nan", F. H. MEYER.

